67-72 4x4 NV4500 spacing questions
 

Hey guys,

Those of you who have swapped in the NV4500 into your 4x4, what difficulties did you have in spacing everything? Mainly engine position and transmission crossmember?

My setup is a 71' SWB, 4x4, lifted 4", with bench seat, using an NV4500/NP205 in its shortest configuration - 32 spline round pattern NP205 mated to the NV4500 without any spacers. I also have an advance adapters bellhousing to use mechanical clutch.

As of right now the rear 4x4 engine position works but its tight. The HEI clears but I'm worried about the cabs opening for the clutch rod getting so close to the valve covers (I have tall valve covers too :rolleyes:). Both shifters seem to clear just fine without touching the seat.

http://i.imgur.com/HKlYt0Hl.jpg

For those of you who have moved the engine forward, did you have to drill out new holes? It seems like I could either move it forward about 2 inches or 4 inches based on the factory holes.

http://i.imgur.com/hBjD2Fbl.jpg
http://i.imgur.com/ZSEG1Vll.jpg

Also it looks like I need to lower the transmission crossmember as the cabs floor is contacting the transfer case. I've seen other members use 2x2" or 2.5x2.5" spacer to lower the crossmember. In doing that, did you adjust your pinion angle? Without adding the spacers, my driveline angle is 2-4 degrees (angle found at transmission yoke).


Please let me know you experiences. Thanks for the help! :chevy:

Re: 67-72 4x4 NV4500 spacing questions
 

Before you go lowering the x-member make sure the cab mounts are not collapsed first

Re: 67-72 4x4 NV4500 spacing questions
 

Good thought kwmech. Mounts are poly and look to be in good shape.

Based on Ryanroo’s build I will need to lower the crossmember. I hope to hear others experiences before I make any changes.

Re: 67-72 4x4 NV4500 spacing questions
 

I moved the engine forward about 1", and modified the trans crossmember to move the mount back which left the crossmember in the original position. The 4500 coupler is longer and moves the tcase back so if you are using the frame mount you will need to drill new holes for that as well as the engine cradle. I've done this two times on my truck first with a mechanical clutch and AA bellhousing and coupler and currently a round pattern 205 on the factory coupler with a hydraulic clutch (much smoother). You'll need to build a mount for the tcase shifter and cut clearence in the adapter for the shifter rod. Also my transmission had an annoying leak between the adapter and tcase which turned out to be caused by the tcase input shaft seal retainer contacting the bottom of the counter bore in the adapter before the gasket got compressed. Sounds like a lot of work but very much worth it. I didn't have any clearence problems with the floor.

Re: 67-72 4x4 NV4500 spacing questions
 

TIMCHNE,

So you moved the engine forward 1" and left the transmission crossmember in its original position (4 speed?) ? Did you drill new holes in the frame for the engine crossmember or use factory holes?

When you say you modified the tranmission crossmember, did you lower it in anyway? how was the condition of the rubber/poly transmission mount? I wonder if I'm having cab clearance issues because my mounts are new.

Re: 67-72 4x4 NV4500 spacing questions
 

I did drill new holes in the frame for the engine cradle, I like the extra room for the HEI. I used the original rubber trans mounts. I didn't take pictures of the trans member mods at the time, I'll try to get some tomorrow. I didn't lower it just cut out and offset the the ridge on the bottom that has the holes for the mount bolts

Re: 67-72 4x4 NV4500 spacing questions
 

Thanks for info TIMCHNE, I'd love to see some pictures when you get a chance.

As of right now, I think I'm going to add 1" spacers to the transmission crossmember and see if I can live with the fitment - mainly to see if the small tilt down will make the HEI hit the firewall. If not, I'll move the engine forward.

Re: 67-72 4x4 NV4500 spacing questions
 

I forgot that I did build a spacer on top of the mounts for the tcase and I probably lowered the tcase in the process.

Re: 67-72 4x4 NV4500 spacing questions
 

The spacer has offset made into it as well.

Re: 67-72 4x4 NV4500 spacing questions
 

Better pic